The cost-effectiveness of repairing ruptured abdominal aortic aneurysms

Cost-effectiveness and cost–utility of endovascular versus open repair of ruptured abdominal aortic aneurysm in the Amsterdam Acute Aneurysm Trial

Background

Minimally invasive endovascular aneurysm repair (EVAR) could be a surgical technique that improves outcome of patients with ruptured abdominal aortic aneurysm (rAAA). The aim of this study was to analyse the cost-effectiveness and cost–utility of EVAR compared with standard open repair (OR) in the treatment of rAAA, with costs per 30-day and 6-month survivor as outcome parameters.

Methods

Resource use was determined from the Amsterdam Acute Aneurysm (AJAX) trial, a multicentre randomized trial comparing EVAR with OR in patients with rAAA. The analysis was performed from a provider perspective. All costs were calculated as if all patients had been treated in the same hospital (Onze Lieve Vrouwe Gasthuis, teaching hospital).

Results

A total of 116 patients were randomized. The 30-day mortality rate was 21 per cent after EVAR and 25 per cent for OR: absolute risk reduction (ARR) 4·4 (95 per cent confidence interval (c.i.) –11·0 to 19·7) per cent. At 6 months, the total mortality rate for EVAR was 28 per cent, compared with 31 per cent among those assigned to OR: ARR 2·4 (−14·2 to 19·0) per cent. The mean cost difference between EVAR and OR was €5306 (95 per cent c.i. –1854 to 12 659) at 30 days and €10 189 (−2477 to 24 506) at 6 months. The incremental cost-effectiveness ratio per prevented death was €120 591 at 30 days and €424 542 at 6 months. There was no significant difference in quality of life between EVAR and OR. Nor was EVAR superior regarding cost–utility.

Conclusion

EVAR may be more effective for rAAA, but its increased costs mean that it is unaffordable based on current standards of societal willingness-to-pay for health gains.

The Cost Effectiveness of Hand Held Ultrasound Scanning for Abdominal Aortic Aneurysm in Older Males with a History of Smoking

Objective: Abdominal aortic aneurysm (AAA) is a serious illness occurring in 1 of 20 older men. Guidelines emphasize the role of ultrasound scanning for patients at risk of AAA, yet the cost effectiveness of such scanning remains uncertain. New pocket mobile echocardiography (PME) devices may enhance the cost effectiveness of such scanning due to its low cost, ability to be used in primary care settings, and high degree of accuracy. This study performs cost utility analyses (CUAs) comparing opportunistic scanning for AAA using a PME to usual care for a hypothetical cohort of 10,000 male smokers age 65+. Methods: The study compares the incremental cost per quality-adjusted life year (QALY) gained for three alternative strategies over a 5-year time horizon. The study used a decision analytic simulation model to calculate the incremental cost utility for the different strategies. Three alternative criteria for surgical intervention were considered via scanning according to aneurysm size. These treatment strategies were compared to a control group that received no scanning. Model input values are taken from the literature. Sensitivity analysis was performed to gauge the robustness of the results. Results: Opportunistic scanning is cost effective. Indeed, when surgical intervention is limited to medium (5.0-5.4 cm) or large (≥5.5 cm) aneurysms, such scanning is dominant; that is, it costs less and increases QALYs compared to usual care. When surgical intervention is extended to small (4.0-4.9 cm) aneurysms, scanning remains cost effective ($64,156 per QALY vs. $100,000 threshold). The results are robust to alternative plausible model input values. Conclusion: These findings suggest that primary care physicians with proper training should consider PMEs as a cost effective method to opportunistically scan and manage AAA patients among older males who have a history of smoking.

Screening for abdominal aortic aneurysms

Ruptured AAA ranks as the 15th leading cause of death overall in the United States, and the 10th leading cause of death in men older than 55 years. Early identification of AAA can save livesand diminish cost. Screening programs havebeen implemented and studied in other countries and have shown a measurable and significant reduction in overall rate of aneurysm-related death. Currently, one-time screening of a small number of ever-smoking men when they turn 65 screening is not widely used in the United States and Medicare, at best, provides one-time screening of a small number of ever-smoking men when they turn 65 years old. Because more than 30,000 individuals in the United States die each year of ruptured AAA, a great deal of progress must be made to eradicate rupture from aneurysmal disease. A more comprehensive system of screening is required and this should be uniformly applied to the U.S. population. It is hoped that scoring systems such as the one outlined in this article, if widely adopted, can greatly enhance screening for aneurysmal disease and prevent the high mortality that stems from this serious vascular disease.

Survival and outcome of neurosurgical patients requiring ventilatory support after intensive care unit stay

OBJECTIVE

The aim of this study was to analyze the clinical outcome of severely ill neurosurgical patients whose need for artificial life support was extended. We sought to determine whether these patients benefit from extended treatment both in life expectancy and quality of life. Furthermore, we evaluated the direct cost of the neurosurgical treatment.

METHODS

The study group comprised a consecutive series of 346 neurosurgical patients in poor condition who were discharged from the intensive care unit but still in need of artificial respiratory support. The patients had various neurosurgical diagnoses and were treated between 2000 and 2003 at the Department of Neurosurgery, Helsinki University Central Hospital. We followed the outcome of these patients by specially formatted questionnaires 6 months and 1, 2, and 5 years after treatment. Their health-related quality of life was evaluated with EuroQol EQ-5D; quality-adjusted life years (QALY) gained with the treatment and the costs of a QALY were calculated.

RESULTS

The median follow-up time was 5 years. The mortality rate was 27% at 30 days, 45% at 1 year, and 59% at 5 years after treatment. Of the patients, 20% had a good recovery (Glasgow Outcome Scale [GOS] scores 4 and 5), 18% had severe disability (GOS score 3), none was in a vegetative state (GOS score 2), 59% were dead (GOS score 1), and 3% were lost to follow-up. Of the survivors, 69% lived at home, 22% in a nursing home, 2% were in a hospital, and 7% were lost to follow-up. The median EQ-5D index value was lower than the median index value for the general population: 0.71 (25th percentile [Q1] 0.38 and 75th percentile [Q3] 0.85) versus 0.85 (Q1 0.73 and Q3 1.00). The median cost of the direct neurosurgical treatment per patient was 15,000 euros (25th percentile, 10,000 euros 75th percentile, 22,000 euros). Surviving patients gained a mean of 17 +/- 13 QALYs. The cost of 1 QALY was 2521 euros.

CONCLUSION

Prolonged intensive care unit and step-down unit treatment of critically ill neurosurgical patients seems to be clinically justified. Moreover, direct costs of neurosurgical treatment were reasonably low.

More patients are treated for nonruptured abdominal aortic aneurysms, but the proportion of women remains unchanged

BACKGROUND

Large variations in the intervention rates for ruptured and nonruptured abdominal aortic aneurysm (AAA) over time have been reported, both decreasing and increasing numbers. Women have been reported to constitute an increasing proportion of patients treated for several manifestations of cardiovascular disease; whether a similar trend is true for AAA is not well understood. This study investigated recent temporal trends in a complete national register regarding the number and type of procedure performed for AAA, and outcome, with special emphasis on gender differences.

METHODS

Data for all individuals treated for nonruptured or ruptured AAA in Sweden (1990 to 2005) were obtained from the Swedish National Board of Health and Welfare (NBHW). A total of 14369 individuals were identified; 2327 (16%) were women. Date and type of intervention, date and cause of death, age, and sex were included in the statistical model.

RESULTS

There was a relative annual increase in interventions for nonruptured AAA; 4% for women (P < .0001) and 2% for men (P < .0001). No significant trends were observed for interventions for rupture during the observation period. No significant increase in the proportion of women was recorded for nonrupture (17%) or rupture (15%). Women had higher crude 30-day mortality rate than men after treatment for both nonruptured (5.7% vs 4.9%) and ruptured (41.9% vs 36.8%) AAA. In a logistic regression model, survival improved over time after intervention for nonrupture (P < .0001) and rupture (P < .0001). Increasing age (P < .0001 for both nonrupture and rupture) but not sex (P = .49 for non rupture and P = .42 for rupture) had a negative influence on mortality.

CONCLUSION

Interventions for nonruptured but not for ruptured AAA increased over time, with an expected rapid increase of endovascular repair in the nonruptured group. The unchanged fraction of women over time possibly reflects the true distribution of AAA between the sexes. The outcome after treatment for both nonruptured and ruptured AAA improved, as anticipated, over time. No increase in mortality among women was recorded after adjustment for age.

A sustained mortality benefit from screening for abdominal aortic aneurysm

BACKGROUND

Longer-term mortality benefit and cost-effectiveness for abdominal aortic aneurysm (AAA) screening are uncertain.

OBJECTIVE

To estimate the benefits, in terms of AAA-related and all-cause mortality, and cost-effectiveness of ultrasonography screening for AAA in a group that was invited to screening compared with a group that was not invited at a mean 7-year follow-up.

DESIGN

Randomized trial.

SETTING

4 centers in the United Kingdom.

PATIENTS

Population-based sample of 67,770 men age 65 to 74 years.

INTERVENTION

Patients with an AAA detected at screening had surveillance and were offered surgery after predefined criteria were met.

MEASUREMENTS

Mortality data were obtained after flagging on the national database. Unit costs obtained from large samples were applied to individual event data for the cost analysis.

RESULTS

The hazard ratio was 0.53 (95% CI, 0.42 to 0.68) for AAA-related mortality in the group invited for screening. The rupture rate in men with normal results on initial ultrasonography has remained low: 0.54 rupture (CI, 0.25 to 1.02 ruptures) per 10 000 person-years. In terms of all-cause mortality, the observed hazard ratio was 0.96 (CI, 0.93 to 1.00). At the 7-year follow-up, cost-effectiveness was estimated at $19 500 (CI, $12,400 to $39,800) per life-year gained based on AAA-related mortality and $7600 (CI, $3300 to infinity) per life-year gained based on all-cause death. (All values are reported in U.S. dollars [U.K. 1 pound sterling = U.S. $1.58]).

LIMITATION

Inclusion of deaths from aortic aneurysm at an unspecified site, which may include some thoracic aortic aneurysms, may have underestimated the treatment effect.

CONCLUSIONS

These results from a large, pragmatic randomized trial show that the early mortality benefit of screening ultrasonography for AAA is maintained in the longer term and that the cost-effectiveness of screening improves over time. International Standard Randomized Controlled Trial registration number: ISRCTN37381646.

Acute Abdominal Aortic Aneurysms: Cost Analysis of Endovascular Repair and Open Surgery in Hemodynamically Stable Patients with 1-year Follow-up

PURPOSE

To retrospectively assess the in-hospital and 1-year follow-up costs of endovascular aneurysm repair and conventional open surgery in patients with acute infrarenal abdominal aortic aneurysm (AAA) by using a resource-use approach.

MATERIALS AND METHODS

Institutional Review Board approval was obtained, and informed consent was waived. In-hospital costs for all consecutive patients (61 men, six women; mean age, 72.0 years) who underwent endovascular repair (n = 32) or open surgery (n = 35) for acute infrarenal AAA from January 1, 2001, to December 31, 2004, were assessed by using a resource-use approach. Patients who did not undergo computed tomography before the procedure were excluded from analysis. One-year follow-up costs were complete for 30 patients who underwent endovascular repair and for 34 patients who underwent open surgery. Costs were assessed from a health care perspective. Mean costs were calculated for each treatment group and were compared by using the Mann-Whitney U test (alpha = .05). The influence of clinical variables on the total in-hospital cost was investigated by using univariate and multivariate analyses. Costs were expressed in euros for the year 2003.

RESULTS

Sex, age, and comorbidity did not differ between treatment groups (P > .05). The mean total in-hospital costs were lower for patients who underwent endovascular repair than for those who underwent open surgery (euro20 767 vs euro35 470, respectively; P = .004). The total costs, including those for 1-year follow-up, were euro23 588 for patients who underwent endovascular repair and euro36 448 for those who underwent open surgery (P = .05). The results of multivariate analysis indicated that complications had a significant influence on total in-hospital cost; patients who had complications incurred total in-hospital costs that were 2.27 times higher than those for patients who had no complications.

CONCLUSION

Total in-hospital costs and total overall costs, which included 1-year follow-up costs, were lower in patients with acute AAA who underwent endovascular repair than in those who underwent open surgery.

Utility of surgery for ruptured abdominal aortic aneurysm

Our aim was to assess the utility of surgery for ruptured abdominal aortic aneurysm (RAAA) using the number of quality-adjusted life years (QALYs) in a retrospective study with cross-sectional quality-of-life (QoL) evaluation. During a 7-year period up to 2002, 242 of 269 (90%) patients with RAAA underwent surgery. Survivors were sent the EQ-5D self-administered questionnaire to assess their long-term outcome. EQ-5D single index values were calculated for each survivor and combined with age- and sex-adjusted Finnish life tables to obtain QALY estimates. Total hospital mortality (90-day) and operative mortality (30-day) were 140 of 269 (52.0%) and 106 of 242 (43.8%), respectively. Of the 129 surviving patients, 111 were available for QoL evaluation. The response rate was 85%. The mean (range) number of QALYs after RAAA was 4.1 (0-30.9) for all and 8.5 (0.2-30.9) for hospital survivors. Young age and low Glasgow Aneurysm Score were associated with a high number of QALYs irrespective of the statistical method used for analysis. Successful repair of RAAA was able to lend considerable benefit as measured by QALYs.

Cost Effectiveness of Chest Computed Tomography After Lung Cancer Resection: A Decision Analysis Model

BACKGROUND

Postoperative surveillance with chest computed tomography (CT) is often performed in patients who have undergone resection of non-small cell lung cancer (NSCLC), despite lack of supporting data. This study involves the creation of a decision analysis model to predict the cost effectiveness of postoperative surveillance CT.

METHODS

A decision analysis model was created in which a hypothetical cohort of patients underwent annual chest CT after resection of a stage IA NSCLC. The incidence of second primary lung cancer (SPLC), sensitivity and specificity of CT, as well as survival after resection of initial primary and SPLC were derived from published literature. The cost of CT and other procedures prompted by a positive finding on CT was calculated from Medicare reimbursement schedules. Cost effectiveness was defined as a cost of less than 60,000 dollars per quality-adjusted life-year gained in the cohort under surveillance compared with controls under no surveillance.

RESULTS

In the initial (base case) analysis, the cost of surveillance CT was 47,676 dollars per quality-adjusted life-year gained, implying cost effectiveness. However, factors that rendered surveillance CT cost ineffective were (1) age at entry into the surveillance program greater than 65 years, (2) cost of CT greater than 700 dollars, (3) incidence of SPLC of less than 1.6% per patient per year of follow-up, and (4) a false positive rate of surveillance CT greater than 14%.

CONCLUSIONS

Surveillance with postoperative CT may be a cost-effective intervention to detect SPLC in selected patients with previously resected stage IA NSCLC.

Abdominal aortic aneurysm (AAA): cost-effectiveness of screening, surveillance of intermediate-sized AAA, and management of symptomatic AAA

Physicians must make decisions about screening patients for abdominal aortic aneurysms (AAAs), monitoring or referring for surgery patients with AAAs of various sizes, and assessing patients with symptoms that may be related to AAAs. This review article analyzes the evidence for each scenario. The effectiveness and cost-effectiveness of screening for AAA is based on results from four randomized controlled trials. A cost-effectiveness analysis using a Markov model showed that ultrasound screening of white men beginning at age 65 is both effective and cost-effective in preventing AAA-related death. Such screening would have a small but real impact over a 20-year period in these men. For patients with a known AAA-which is often detected incidentally-the evidence clearly suggests periodic ultrasound surveillance for those with small AAAs (3.0-3.9 cm in diameter) and elective surgical repair for those with large AAAs (>or=5.5 cm). Two recent randomized controlled trials have shown that early surgical repair confers no survival benefit compared with periodic surveillance for patients with intermediate-sized AAAs (4.0-5.5 cm in diameter), so those patients can also be monitored. Some centers choose to increase the frequency of monitoring to every 3 to 6 months when the AAA reaches 5.0 cm. Factors to consider in assessing symptomatic patients include the high risk of life-threatening conditions, the potential increased risk of death or poor outcome with delay in diagnosis, the limitations of ultrasound in identifying whether symptoms are due to known or suspected AAA, and the timely availability of computed tomography or other imaging tests. If available, computed tomography is preferred in patients with recent or severe symptoms, since it is better at detecting retroperitoneal hemorrhage and other complications and in providing preoperative definition of the anatomy.

Resource utilization and outcomes: effect of transfer on patients with ruptured abdominal aortic aneurysms

We evaluated the transfer of patients with the diagnosis of a ruptured AAA (rAAA) from community centers to a tertiary care center. Our purpose was to identify factors associated with mortality and outcomes following the open repair of rAAA and to evaluate the differences between transferred and nontransferred patients. All patients who underwent repair of rAAA at our institution between 1995 and 2002 were retrospectively reviewed. Univariate and multivariate analysis was performed to identify patient specific factors on presentation and intraoperatively. Fifty-two patients underwent repair of rAAA, 20 patients were transferred to our institution. The overall mortality rate was 67%. The mortality rates for nontransferred and transferred groups were 69% and 65%, respectively. The incidence of mortality within 24 hr of surgery was significantly higher in the patients who were not transferred, 10 vs. 41% (p < 0.05). Patient-specific factors assessed for impact on survival by logistic regression included decreased body temperature on arrival to our institution (p = 0.02) and free rupture (p = 0.05). Of intraoperative factors tested, low systolic blood pressure was significantly associated with mortality (p = 0.05). No difference in total length of stay was noted. Transfer patients' length of stay in the intensive care unit was significantly greater than that of nontransferred patients (18.8 +/- vs. 7.3 +/- days, p < 0.05). The difference in ICU cost was dollar 36,000 among groups. We found the acceptance of transfer patients from community centers with rAAA did not adversely affect patient survival. Transferred patients had an over twofold increases in ICU days used. The identification of hypothermia was the single independent factor associated with poor survival and may be a marker for transfer selection. Given reduced reimbursements and increased utilization, tertiary care centers will need to consider the economic ramifications of accepting transfer patients with rAAA.

Management of Abdominal Aortic Aneurysms

Abdominal aortic aneurysms (AAAs) are a lethal disease. Ultrasound is the modality of choice for screening patients for AAAs. It is reasonable to screen patients over age 60, particularly men, women with cardiovascular risk factors, smokers, and patients with a family history of AAAs. Patients with small (< 5.5 cm) AAAs should be followed with serial ultrasound. Medical management should focus on treating comorbidities, particularly those that put patients at risk for other cardiovascular diseases. Smoking cessation is mandatory in these patients. Patients with large or symptomatic AAAs should be evaluated for surgery; this includes careful imaging of the abdomen, aggressive treatment of comorbidities, and perioperative beta blockade. Endovascular repair has lower short-term morbidity compared with conventional open repair. Trials assessing long-term results are in progress. Basic science and translational research focusing on the underlying pathogenesis of AAAs will likely pave the way for medical therapies in the future.

Functional outcome after open repair of ruptured abdominal aortic aneurysm

BACKGROUND

Outcome after operative repair of ruptured abdominal aortic aneurysm (AAA) has traditionally been assessed in terms of survival. This study examines the functional outcome of patients who survive operation.

METHODS

Consecutive patients who survived open repair over an 18-month period were entered into a prospective case-control study. Age- and sex-matched controls were identified from patients undergoing elective AAA repair. The Short Form-36 health survey was administered to both groups of patients at 6 months after operation. Results were compared with the expected scores for an age- and sex-matched normal UK population.

RESULTS

Fifty-seven patients underwent open repair of a ruptured AAA, and 30 survived; no patient was lost to follow-up. There were no significant differences in quality of life between patients who had an emergency repair and those who had an elective repair. Both of these groups had poorer health-related quality of life outcomes than the matched normal population. Surprisingly, compared with the normal population, patients after elective repair had poorer outcomes in more health domains than patients who survived emergency operation.

CONCLUSIONS

Survivors of ruptured AAA repair have a good functional outcome within 6 months of operation.

Quality of Life After Repair of Ruptured Abdominal Aortic Aneurysm

BACKGROUND

Ruptured abdominal aortic aneurysm (AAA) continues to be associated with high operative mortality. Though survivors can expect to return to a normal life expectancy, their postoperative health related quality of life (HRQoL) remains uncertain. This review examines HRQoL following operative repair of ruptured AAA.

METHODS

PreMedline, Medline and Embase databases were searched for clinical studies relating to quality of life following repair of ruptured AAA. Reference lists of relevant papers were also reviewed.

RESULTS

Fourteen retrospective-observational studies of postoperative quality of life following repair of ruptured AAA were identified. Both validated and non-validated tools for generic HRQoL assessment were used. All but one study showed no significant difference in overall HRQoL following ruptured AAA repair when compared to both the normal age-adjusted population and patients undergoing elective repair of intact AAA. However, survivors of ruptured AAA did exhibit significant reductions in the isolated domains of physical function, social behaviour and general well-being.

CONCLUSIONS

There are few studies of HRQoL following repair of ruptured AAA. These reports are retrospective, have small sample sizes and use generic instruments for HRQoL assessment. The findings suggest that survivors of ruptured AAA may attain a similar functional outcome to patients undergoing elective AAA repair and the age-matched healthy population. However, these results must be interpreted with caution and further prospective study is required.

Lifetime Gain Related to Cost of Repair of Ruptured Abdominal Aortic Aneurysm in Octogenarians

OBJECTIVE

To report cost related to gained life years after repair of ruptured abdominal aortic aneurysms in patients aged 80 or older.

DESIGN

A retrospective study based on prospectively registered data.

PATIENTS AND METHODS

Fifty-three patients aged 80 or older were operated on for ruptured abdominal aortic aneurysm over a 20-year period from 1983 to 2002. Thirty-one (58%) patients had systolic BT <80 mmHg. Operative mortality (<30 days) and long-term survival were studied. The number of life-years gained from the operations was estimated. Based on diagnose related group (DRG) values, the cost of each gained life-year was calculated.

RESULTS

The operative mortality was 47%. Long-term survival of those patients who survived the operation was similar to that of an age and sex matched population. The 53 operations resulted in 145 gained life-years, which leaves a mean survival of 2.7 years of all the patients and 5.2 years of those who survived the operation. The estimated cost per gained life year was euro6817.

CONCLUSIONS

The operative mortality of ruptured abdominal aortic aneurysm remains high. The long-term survival of patients who survive the operation is acceptable. The price of each gained life-year is low, as compared to other established treatment modalities. Improved results with endovascular treatment may even decrease the cost per gained life year.

A cost analysis of surgery for ruptured abdominal aortic aneurysm

OBJECTIVE

This study compares our costs of salvaging patients with ruptured abdominal aortic aneurysms (AAA) with the costs for unruptured AAAs.

METHODS

Details of all AAAs presenting over 18 months were obtained. Costs of repair were carefully calculated for each case and were based upon ITU and ward stay and the use of theatre, radiology and pathology services. We compared the costs in unruptured AAAs with both uncomplicated ruptures and ruptures with one or more system failure.

RESULTS

The mortality rate for ruptures undergoing repair was 18% and for elective repairs was 1.6%. The median cost for uncomplicated ruptures was 6427 Pounds (range 2012-13,756 Pounds). For 12 complicated ruptures, it was 20,075 Pounds (range 13,864-166,446 Pounds), and for 63 unruptured AAAs, was 4762 Pounds (range 2925-47,499 Pounds).

CONCLUSION

Relatively low operative mortality rates for ruptured AAA repair can be achieved but this comes at substantial cost. On average, a ruptured AAA requiring system support costs four times as much as an elective repair.

Ruptured aneurysm of the infrarenal abdominal aorta: impact of age and postoperative complications on mortality

Between 1985 and 2000, a total of 871 patients underwent surgical treatment for infrarenal abdominal aortic aneurysm (AAA), including 98 (11.2%) presenting with ruptured abdominal aortic aneurysms (RAAA). An optimized operative protocol was used to treat 77 RAAA starting in January 1989. The main features of the optimized protocol are routine use of intraoperative autotransfusion, revascularization by aortoaortic bypass, absence of systemic heparinization, and use of a collagen-impregnated prosthesis. Intraoperative mortality (IOM) was 3.8%. Postoperative mortality at 1 month (POM1) was 25.9% and postoperative mortality at 3 months (POM3) was 33.7%. Heart failure (p <0.001), hemodynamic shock (p <0.001), and hemorrhage (p = 0.04) were the only complications correlated with POM1. Pneumonia (p = 0.01) and sepsis (p = 0.01) were the only complications correlated with POM3. Isolated acute renal insufficiency was not a significant risk factor for postoperative mortality. Using a cutoff of 75 years, there was a significant age-related difference (p = 0.025) for POM1 but not for IOM and POM3. The findings of this study show that optimizing the operative protocol decreases mortality related to RAAA. The main predictor of POM1 was hemodynamic status while the main predictor of POM3 was infection. Isolated acute renal insufficiency was not a risk factor for mortality. Age should not be considered a contraindication for operative treatment.

Mortality, morbidity, and costs of ruptured and elective abdominal aortic aneurysm repairs in Nova Scotia, Canada

Ruptured abdominal aortic aneurysms (RAAA) have a 78-94% mortality rate. If cost-effectiveness of screening programs for abdominal aortic aneurysms (AAA) are to be assessed, direct costs for RAAA repairs and elective AAA (EAAA) repairs are required. This study reports mortality, morbidity, and direct costs for RAAA and EAAA repairs in Nova Scotia in 1997-1998 and also compares Nova Scotia and U.S. costs. We performed a retrospective study of 41 consecutive RAAA and 48 randomly selected EAAA patients. Average total costs for RAAA repair were significantly greater than those for EAAA repair (direct costs: $15,854 vs. $9673; direct plus overhead costs: $18,899 vs. $12,324 [pricing in 1998 Canadian dollars]). Intensive care unit length of stay and blood product usage were the most substantial direct cost differentials ($3593 and $2106). Direct cost for preoperative testing and surveillance was greater in the EAAA group ($839 vs. $33). Estimates of U.S. in-hospital RAAA and EAAA repair costs are more than 1.5 times Nova Scotia costs. Direct in-hospital RAAA repair costs are $6181 more than EAAA repair costs. These in-hospital cost data are key cost elements required to assess the cost-effectiveness of various screening strategies for earlier detection and monitoring of AAA within high-risk populations in Canada. Further studies are required to estimate cost per quality-adjusted-life-year gained for various AAA screening and monitoring strategies in Canada.

The principles of cost-effectiveness analysis and their application

The current healthcare environment requires the evaluation of both the costs and benefits of alternative interventions for a given clinical problem. Given the increased interest in the economic evaluation of healthcare interventions, this article briefly defines various forms of economic evaluations and describes some useful steps for conducting appraisals of cost-effectiveness analyses. Studies of competing methods of treatment of abdominal aortic aneurysms greater than 5 cm are used as a clinical example of interest to the readers of this Journal. Rather than actually conducting such an analysis with existing data, we describe the principles for conducting or reviewing an economic analysis with factitious data.

The cost-effectiveness of a "quick-screen" program for abdominal aortic aneurysms

BACKGROUND

The incidence of abdominal aortic aneurysm (AAA) is increasing, and the prognosis of ruptured AAA remains dismal. Early diagnosis and intervention are crucial. We designed this study to determine whether selected population screening with a brief "quick-screen" ultrasound could be cost-effective.

METHODS

A series of 25 patients with risk factors for AAA were evaluated in a blinded fashion by a quick-screen ultrasound and a full conventional study. Times and accuracy for the 2 approaches were compared. An analysis of the cost-effectiveness of screening for AAA was then performed using a Markov model. We determined the long-term survival in quality-adjusted life years and lifetime costs for a hypothetical cohort of 70-year-old males undergoing either AAA screening or not. Our measure of outcome was the cost-effectiveness ratio (CER).

RESULTS

The average time for a quick screen was one-sixth that of a conventional study (4 vs 24 minutes). The accuracy of the quick screen was 100%. In our base-case analysis, screening for AAA was cost-effective with a CER of $11,215. Society usually is willing to pay for interventions with CER of less than $60,000 (eg, CER for coronary artery bypass grafting, $9500; breast cancer screening, $16,000). In sensitivity analysis, reducing the cost of screening from $259 (approximate Medicare reimbursement) to $40 (the quick screen) improved the CER to $6850. Moreover, screening populations with increased prevalence of AAA (eg, male with family history [18%]) further improved the CER.

CONCLUSIONS

Our analysis demonstrates that ultrasound screening for AAA should be offered to all males above the age of 60. Widespread screening for AAA should be adopted and reimbursed by Medicare and other insurers.

A meta-analysis of 50 years of ruptured abdominal aortic aneurysm repair

BACKGROUND

Operative repair of ruptured abdominal aortic aneurysm (RAAA) is associated with a high mortality rate but reported figures vary widely. The aim of this study was to estimate the operative mortality of RAAA repair and determine how it has changed over time.

METHODS

A meta-analysis of all English language literature quoting figures for operative mortality of RAAA repair.

RESULTS

The pooled estimate for the overall operative mortality rate of RAAA repair from 1955 to 1998 was 48 (95 per cent confidence interval 46 to 50) per cent. Meta-regression analysis of operative mortality over time demonstrated a constant reduction of approximately 3.5 per cent per decade (1954-1997) with an operative mortality rate estimate for the year 2000 of 41 per cent. Seventy-seven studies reported intraoperative mortality but, while this appears to have remained constant over time, there was evidence of the presence of publication bias in the subgroup of papers reporting this outcome. There was no evidence of publication bias for the overall operative mortality outcome.

CONCLUSION

Contrary to the conclusion of recent studies, this paper demonstrates a gradual reduction with time in the operative mortality rate of RAAA repair.